Re: [PATCH] Call memcpy in generic mempcpy

[OndÅej BÃlka <neleai at seznam dot cz>]

On Wed, Feb 06, 2013 at 03:19:37PM -0800, Roland McGrath wrote:
> > On 02/06/13 12:53, Ond$,1 yej B,Amlka wrote:
> > >    unsigned long int dstp = (long int) dstpp;
> > ...
> > > +  memcpy (dstpp, srcpp, len);
> > > +  return (void *) (dstp + len);
> > 
> > There's no need to use an integer type, or
> > to do any casts.  Something like this, perhaps?
> > 
> >   char *dstp = dstpp;
> >   memcpy (destpp, srcpp, len);
> >   return dstp + len;
> 
> It's GNU code and can assume GNU C extensions.
> So there isn't even a need for a cast.
> And, it's more efficient to use the return value.
OK.

I also renamed dstpp to dest as that distinction is no longer needed.

2013-02-06   OndÅej BÃlka  <neleai@seznam.cz>

        * string/mempcpy.c: Implement by calling memcpy.

diff --git a/string/mempcpy.c b/string/mempcpy.c
index ba4d1c6..e1aad75 100644
--- a/string/mempcpy.c
+++ b/string/mempcpy.c
@@ -20,48 +20,17 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <string.h>
-#include <memcopy.h>
-#include <pagecopy.h>
 
 #undef mempcpy
 #undef __mempcpy
 
 void *
-__mempcpy (dstpp, srcpp, len)
-     void *dstpp;
-     const void *srcpp;
+__mempcpy (dest, src, len)
+     void *dest;
+     const void *src;
      size_t len;
 {
-  unsigned long int dstp = (long int) dstpp;
-  unsigned long int srcp = (long int) srcpp;
-
-  /* Copy from the beginning to the end.  */
-
-  /* If there not too few bytes to copy, use word copy.  */
-  if (len >= OP_T_THRES)
-    {
-      /* Copy just a few bytes to make DSTP aligned.  */
-      len -= (-dstp) % OPSIZ;
-      BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
-
-      /* Copy whole pages from SRCP to DSTP by virtual address manipulation,
-	 as much as possible.  */
-
-      PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
-
-      /* Copy from SRCP to DSTP taking advantage of the known alignment of
-	 DSTP.  Number of bytes remaining is put in the third argument,
-	 i.e. in LEN.  This number may vary from machine to machine.  */
-
-      WORD_COPY_FWD (dstp, srcp, len, len);
-
-      /* Fall out and copy the tail.  */
-    }
-
-  /* There are just a few bytes to copy.  Use byte memory operations.  */
-  BYTE_COPY_FWD (dstp, srcp, len);
-
-  return (void *) dstp;
+  return memcpy (dest, src, len) + len;
 }
 libc_hidden_def (__mempcpy)
 weak_alias (__mempcpy, mempcpy)